Rotary piston filling machines are well known in the art and a typical example is shown in U.S. Pat. No. 2,958,346, the subject matter of which is incorporated herein by reference thereto. Such machines have a central product reservoir which is provided with a plurality of radially spaced apart cylindrical ports in its lower periphery, the reservoir and ports being adapted to be rotated within a stationary framework about a central vertically extending axis. Associated with each port is a filling station which includes a container support, a valve body which contains a rotary valve and a vertically extending cylinder and piston assembly mounted on top of the valve body. After a container to be filled has been loaded onto a machine of this type it will be moved about the periphery of the machine as the associated piston is caused to be moved upwardly to fill the associated cylinder with a predetermined quantity of fluent material, after which the material will be discharged into the container. Difficulties have been encountered when discharging directly from the valve body into a container, particularly if the fluent material being discharged is of a foamy nature.